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Author Topic: Fuji X-Pro 1  (Read 10436 times)
michael
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« Reply #40 on: March 12, 2012, 06:24:11 AM »
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Film photography is a different activity to digital photography.

They may both be photography and use similar equipment but they're not the same.

Now just how accurate is photography?

If you use thirds and your shutter speed is 1/30 then it is possible that the camera has rounded up from 1/28 or down from 1/35.
If it is rounded down from 1/35 then the 1/30 shot is over exposed by 17%.
That is huge and I don't know how anyone could consider it to be "accurate."

With all due respect, your example is complete nonsense. If you can measure, let alone see the difference in exposure between 1/35 sec and 1/30 sec you'd better show us how, because it flies in the face of both logic and practice.

In any event, most lenses can be adjusted in 1/3rd stop increments, and most electronic shutters are continuous, with almost infinitely variable settings when adjusted by a cameras auto mode. Manually they are in full stop increments, but that's a human factors issue, not a technical limitation.

You are confusing precision with accuracy.

You're right on one thing though. Exposing for digital is different than for film. For digital, there is only one technically optimum exposure when shooting raw, at base ISO, and that's at the maximum exposure that avoids blowing non-specular highlights. Fussing over even a 1/2 stop there though is more like a fetish than concern for optimum technical quality.

Michael
« Last Edit: March 12, 2012, 06:28:21 AM by michael » Logged
Rob C
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« Reply #41 on: March 12, 2012, 08:00:16 AM »
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Don't you just love the breath of fresh air in the morning? Far better than napalm!

Rob C
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dreed
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« Reply #42 on: March 12, 2012, 08:43:39 AM »
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With all due respect, your example is complete nonsense. If you can measure, let alone see the difference in exposure between 1/35 sec and 1/30 sec you'd better show us how, because it flies in the face of both logic and practice.

I must admit that after I wrote that, I was thinking to myself "how can it be that film based photography worked as it did if exposure steps were so limited?" because as you say, the practice would suggest that finer grained shutter speeds are not required for our eyes.

And yes, you're right about the difference of what would be 1/6th of a stop being too difficult to discern - through simulating the before/after with LR I could see the colour change but if I turned away and looked back, it was damn near impossible to pick between the two (or at least I couldn't using the laptop that I'm currently using. Maybe if I tweaked the monitor or glued it to my nose it would be easier to notice the difference.) I suppose I should have tried this out before to test that argument.
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image66
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« Reply #43 on: March 12, 2012, 08:44:12 AM »
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I don't think you know what you are talking about.



If you are interested in dialog, I'll gladly participate. But shutting a person down with this kind of statement is a waste of a good forum. I expect it in Dpreview, not here.
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Rhossydd
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« Reply #44 on: March 12, 2012, 09:10:52 AM »
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And yes, you're right about the difference of what would be 1/6th of a stop being too difficult to discern
If you think the difference between 1/30th and 1/35th is one sixth of a stop you need a better understanding of the fundamentals before you start pedantic arguments here.
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jeremypayne
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« Reply #45 on: March 12, 2012, 09:15:23 AM »
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If you are interested in dialog, I'll gladly participate. But shutting a person down with this kind of statement is a waste of a good forum. I expect it in Dpreview, not here.

Making stuff up is a "waste of good forum".

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Slobodan Blagojevic
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« Reply #46 on: March 12, 2012, 09:46:09 AM »
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Ok... I admit... I missed this thread initially and got to it when it reached its third page. However, after reading just the OP, all I can eloquently say is:

Booooooo!
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Slobodan

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image66
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« Reply #47 on: March 12, 2012, 10:47:27 AM »
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Making stuff up is a "waste of good forum".



Yes, I have a fertile imagination. Thanks for the compliment. But in this case my fertile imagination is what caused me to question why certain things failed in digital imaging. Questions like when reds blow out, why do they shift to yellow? Why the color shifts when using highlight recovery? This was the basis for quite a bit of research and testing with color charts with and without color filters, comparing numerous Raw converters and looking at the pixel data inside the Raw files themselves.

But I'm guessing that you have done the same thing and came to another conclusion. I didn't test Nikon files so your results might be different. Canon, Panasonic, Minolta and Olympus files, yes; Nikon files, no. That was also why I was specifically mentioning Olympus and Pansonic files. These I know well. Nikon files, not so much. Whatever you know about Raw files with Nikon may not necessarily apply with other brands. The filteration on the sensors is quite different.

Feel free to show me your results that prove that I'm making this up. Sorry, but you cannot use just Lightroom to prove your point. That would be far too easy to debunk so don't even bother going there. You'll need to try harder than that.

On a related note, in your D700, what is the dynamic range of the blue channel under daylight balance? What is it under tungsten after WB adjustment? Is it better to apply WB correction or use a color correction filter?

Simple questions sometimes demand careful analysis and research. These questions can sometimes open up a Pandora's Box.

Ken
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dreed
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« Reply #48 on: March 12, 2012, 10:56:48 AM »
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Ok... I admit... I missed this thread initially and got to it when it reached its third page. However, after reading just the OP, all I can eloquently say is:

Booooooo!

Fine, but I still don't see anything "21st century" in this camera - or most other digital cameras.

Speaking of 21st century, there's only another 7 years before we'll have the Esper Machine (Blade Runner) and whatever camera was used to take that photo.
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image66
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« Reply #49 on: March 12, 2012, 11:57:42 AM »
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Fine, but I still don't see anything "21st century" in this camera - or most other digital cameras.

Speaking of 21st century, there's only another 7 years before we'll have the Esper Machine (Blade Runner) and whatever camera was used to take that photo.

It would definitely be nice to have an ETTR exposure function in the camera with user programmable limits and appropriate protections to keep the colors intact at the upper limit. Technically, this is entirely possible today if the manufacturers put a programmer on it for a week.

The latest/greatest Sekonic meter actually is a fantastic tool in this regard. You create exposure profiles for your films or cameras. With a quick spot meter reading of the highlight you want to put to ETTR, a press of a button will tell you what exposure to use. It's accurate to 1/10 of a stop.

Ken
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michael
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« Reply #50 on: March 12, 2012, 12:51:35 PM »
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I've been lobbying both publicly as well as privately for in-camera ETTR exposure for years, and while several manufacturers I spoken with agree that it makes perfect sense, thus far none have the smarts to implement it. The DNG standard even has a built-in correction factor so that screen review and post processing preview could display a "normalized" image. Alas most camera makers also abjure DNG.

Sigh
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BJL
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« Reply #51 on: March 12, 2012, 01:31:31 PM »
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... if we did the (thought or material) experiment of redesigning a digital camera from scratch without regard to current practices but taking maximum advantage of current technology, we would come up with what we have now. If speed, aperture and sensitivity can be made continuously variable, why not allow them to be?
In my alternate photographic universe, thee would still be settings for shutter speed, and for aperture (but maybe with the option of specifying an effective aperture diameter rather than an aperture ratio, for more direct relevance to DOF), and then a way to specify how light levels in the scene are scaled to digital output levels (maybe metered mid-tones placed at 18% of maximum level, or metered highlights placed at just below maximum level, and including exposure compensation). But there would not be an ISO speed, because that is a carryover from film that does not fit so well with the operation of an electronic light detection signal and processing device, and the one that is most remote from directly describing any feature of the composition.

Instead, gain would be the replacements, and the three parameters of aperture, exposure duration, and "tonal placement" could dictate the degree of gain needed, and do so on a continuous scale. Also, the camera could usually take care of how much of that gain to apply to the analog signal before ADC, how much to apply after ADC as digital rescaling, and how much to simply note in the raw file for subsequent application in post-processing. If the camera's calculation gives "exposure index 729", and this means that the amplifications is such that the maximum output level corresponds to the signal from a well filled to 22% of capacity, why not?
« Last Edit: March 12, 2012, 03:24:49 PM by BJL » Logged
image66
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« Reply #52 on: March 12, 2012, 02:21:05 PM »
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BJL's approach of altering the channel gain on-sensor before A-D conversion has a lot of merit. The roots of this are firmly planted in decades of audio and video processing. Still imaging is actually pretty late to this game. What BJL is suggesting is actually one of the tools at our disposal in scanning film with some scanners and software. It's nothing that need to be invented. Just applied.

The concept that stops is old school and stopless is 21st century has an inverted parallel. I'm a darkroom rat. Grew up in the darkroom, have Dektol in my DNA. The single greatest thing I ever did for the darkroom was buy an RH Designs Stopclock Professional and ZoneMaster II meter. Both operate in..... STOPS! Printing exposures are generally considered infinitely variable. By working in stops and fractions of stops, it not only simplified the process greatly, but achieved levels of accuracy and control never experienced before.

Ken
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opgr
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« Reply #53 on: March 12, 2012, 03:14:46 PM »
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I've been lobbying both publicly as well as privately for in-camera ETTR exposure for years, and while several manufacturers I spoken with agree that it makes perfect sense, thus far none have the smarts to implement it. The DNG standard even has a built-in correction factor so that screen review and post processing preview could display a "normalized" image. Alas most camera makers also abjure DNG.

Sigh

What makes you think the camera isn't already doing this prior to RAW data creation?

And at the danger of repeating myself ad nauseam: suppose the sensor has a non-linear response at its lower and upper bounds, how would you suggest implementing ETTR?
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Oscar Rysdyk
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jeremypayne
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« Reply #54 on: March 12, 2012, 04:17:01 PM »
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Yes, I have a fertile imagination. Thanks for the compliment. But in this case my fertile imagination is what caused me to question why certain things failed in digital imaging. Questions like when reds blow out, why do they shift to yellow? Why the color shifts when using highlight recovery? This was the basis for quite a bit of research and testing with color charts with and without color filters, comparing numerous Raw converters and looking at the pixel data inside the Raw files themselves.

For someone who doesn't have time to directly address the issue at hand, you sure have a lot of time for other stuff and musings ...

Nothing that you have offered explains why Olympus and Panasonic cameras can't benefit from ETTR.  You've made vague references to multiple kinds of green sensels and the fact that the histograms in digital cameras are based on rendered images ... but you have yet to explain your comment that I questioned about Olympus and Panasonic cameras and their unsuitability for ETTR.

I use ETTR techniques with my Panasonic GF1 regularly.
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image66
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« Reply #55 on: March 12, 2012, 10:11:34 PM »
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For someone who doesn't have time to directly address the issue at hand, you sure have a lot of time for other stuff and musings ...

Nothing that you have offered explains why Olympus and Panasonic cameras can't benefit from ETTR.  You've made vague references to multiple kinds of green sensels and the fact that the histograms in digital cameras are based on rendered images ... but you have yet to explain your comment that I questioned about Olympus and Panasonic cameras and their unsuitability for ETTR.

I use ETTR techniques with my Panasonic GF1 regularly.

No, I'm not saying that ETTR can't be used with Olympus/Panasonic files, but that the point where you get color shifts in recovered highlights occurs sooner. Depending on color, this can occur about a half stop away from clipping. This also occurs with other cameras too, but to different degrees of success.

In nature photography there are few exacts. It's definitely a different world than product photography, for example. I'm not sure there are many product photographers who use ETTR. Not only does it add too much variability, but the risk of color shifts is too great.

When you get too close to the cliff with ETTR, bad things can happen. I'm sure I'm not the only one who has reverted to a bracketed shot because I pushed my histogram too far even though it was still within the lines.

Ken

Ken
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jeremypayne
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« Reply #56 on: March 13, 2012, 05:59:41 AM »
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No, I'm not saying that ETTR can't be used with Olympus/Panasonic files, but that the point where you get color shifts in recovered highlights occurs sooner.

Really?  Show us. 

I hope by "recovered" you don't mean to imply that these "highlights" you are "recovering" came from saturated sensels ... as that isn't ETTR ... that's called ETFTTR.
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image66
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« Reply #57 on: March 13, 2012, 09:04:29 AM »
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Really?  Show us. 

I hope by "recovered" you don't mean to imply that these "highlights" you are "recovering" came from saturated sensels ... as that isn't ETTR ... that's called ETFTTR.

I could. But I see where this is going. You have already come to a conclusion, and no facts will prove otherwise. This is one of those no-win situations where if you disagree with the tests, challenge the tester. This is how you have operated in the past.

What I would rather do is get people thinking about this and doing their own controlled testing to know exactly where their system hits the limit. I will say that anybody who thinks the histogram is an accurate representation of what is going on at the sensor is very ill-informed. You will require a balanced light source and a Kodak color test target. Take a series of photos of the target varying the exposure from Five stops under to five stops over. (or to the maximum limit of your lighting and exposure control). Process the files and see what really is happening at the top and bottom points of exposure. It will be an eye opener. Especially as you apply highlight and shadow recovery, but even exposure-compensation will reveal much. What happens with the derived colors (yellow, cyan, magenta) is even more challenging to the conventional wisdom.

This is just the digital equivalent to building log curves. In the B&W photography world, there are those who have done this and understand how the films actually respond. For everybody else, they just overexposed and underdeveloped the film because others said so.

Alas, few will test. The rest will ETTR and end up using the bracketed exposure not knowing why the ETTR shot didn't work right.

Ken
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deejjjaaaa
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« Reply #58 on: March 13, 2012, 09:31:34 AM »
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What I would rather do is get people thinking about this and doing their own controlled testing to know exactly where their system hits the limit. I will say that anybody who thinks the histogram is an accurate representation of what is going on at the sensor is very ill-informed.

Software like rawnalyze (now we have a modern version = www.rawdigger.com) to see the real raw data histogram and UniWB to get in camera histogram as close to the raw data histogram as possible were in place for years... I do not think there are readers on this forum who still think what you allege they think.
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dreed
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« Reply #59 on: March 13, 2012, 09:49:13 AM »
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I've been lobbying both publicly as well as privately for in-camera ETTR exposure for years, and while several manufacturers I spoken with agree that it makes perfect sense, thus far none have the smarts to implement it. The DNG standard even has a built-in correction factor so that screen review and post processing preview could display a "normalized" image. Alas most camera makers also abjure DNG.

In your conversations with manufacturers, have they ever said or hinted at why they have not or will not adopt DNG?
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